Please cite this article in press as: Fontenelle, L. F., et al. Towards a post-traumatic subtype of obsessive–compulsive disorder. Journal of Anxiety Disorders (2012), doi:10.1016/j.janxdis.2011.12.001 ARTICLE IN PRESS G Model ANXDIS-1363; No. of Pages 7 Journal of Anxiety Disorders xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Journal of Anxiety Disorders Towards a post-traumatic subtype of obsessive–compulsive disorder  Leonardo F. Fontenelle a,b,∗ , Luca Cocchi c , Ben J. Harrison c , Roseli G. Shavitt d , Maria Conceic ¸ ão do Rosário e , Ygor A. Ferrão f , Maria Alice de Mathis d , Aristides V. Cordioli g , Murat Yücel c , Christos Pantelis c , Jair de Jesus Mari e , Euripedes C. Miguel d , Albina R. Torres h a Anxiety and Depression Research Program, Institute of Psychiatry, Federal University of Rio de Janeiro, Brazil b Department of Psychiatry and Mental Health, Institute of Community Health, Fluminense Federal University, Brazil c Melbourne Neuropsychiatry Centre, University of Melbourne and Melbourne Health, Australia d Department of Psychiatry, University of São Paulo Medical School, Brazil e Department of Psychiatry, Federal University of São Paulo, Brazil f Department of Psychiatry, Health Sciences Federal University of Porto Alegre, Brazil g Department of Psychiatry, Federal University of Rio Grande do Sul, Brazil h Department of Neurology, Psychology and Psychiatry; Botucatu Medical School, Universidade Estadual Paulista, Brazil a r t i c l e i n f o Article history: Received 18 May 2011 Received in revised form 29 November 2011 Accepted 4 December 2011 Keywords: Obsessive–compulsive disorder Post-traumatic stress disorder Traumatic stress Traumatic life-events Comorbidity a b s t r a c t We evaluated whether traumatic events are associated with a distinctive pattern of socio-demographic and clinical features of obsessive–compulsive disorder (OCD). We compared socio-demographic and clinical features of 106 patients developing OCD after post-traumatic stress disorder (PTSD; termed post- traumatic OCD), 41 patients developing OCD before PTSD (pre-traumatic OCD), and 810 OCD patients without any history of PTSD (non-traumatic OCD) using multinomial logistic regression analysis. A later age at onset of OCD, self-mutilation disorder, history of suicide plans, panic disorder with agoraphobia, and compulsive buying disorder were independently related to post-traumatic OCD. In contrast, ear- lier age at OCD onset, alcohol-related disorders, contamination-washing symptoms, and self-mutilation disorder were all independently associated with pre-traumatic OCD. In addition, patients with post- traumatic OCD without a previous history of obsessive–compulsive symptoms (OCS) showed lower educational levels, greater rates of contamination-washing symptoms, and more severe miscellaneous symptoms as compared to post-traumatic OCD patients with a history of OCS. © 2011 Elsevier Ltd. All rights reserved. 1. Introduction Obsessive–compulsive disorder (OCD) is characterized by rumi- native and preoccupying mental agonies, i.e. obsessions, and perseverative and ritualized behaviors, i.e. compulsions (Murphy, Timpano, Wheaton, Greenberg, & Miguel, 2010). Unfortunately, there is an incomplete understanding of the etiology of OCD and how to best conceptualize and treat its complex and heterogeneous symptoms. Although genetics is thought to play an important role in the etiology of OCD [as suggested by family, twin, association and linkage studies (Nestadt, Grados, & Samuels, 2010)], multiple non-genetic components are also likely to be involved. In particular,  This research was supported by a Conselho Nacional de Desenvolvimento Científico e Tecnológico Grant (420.122/2005-2) and National Health and Medical Research Council of Australia Grants Awarded to Ben J Harrison (ID No. 628509) and Murat Yücel (ID No. 509345). ∗ Corresponding author at: Rua Visconde de Pirajá, 547, Sala 719, Ipanema, CEP: 22410-003 Rio de Janeiro, Brazil. Tel.: +55 21 22394919; fax: +55 21 22394919. E-mail address: lfontenelle@gmail.com (L.F. Fontenelle). it has been suggested that general stressful life events may act as an etiological factor in the development of OCD in those without a family history of the illness (Cath, van Grootheest, Willemsen, van Oppen, & Boomsma, 2008). Although life events have long been considered to play a key role in the development of OCD (Pollitt, 1957), very few studies have addressed this issue directly or systematically. Initial attempts to assess the role of general precipitants in OCD were completed using non-validated instruments. As a consequence, these early studies reported highly variable rates of stressful life events prior to the emergence of OCD, ranging from 30 to 78% (Greer & Cawley, 1966; Ledwidge, 1982). More recently, standardized and well-validated tools (i.e. Paykel’s Recent Life Events Interview) have been used to systematically assess the role of stressful life events in the genesis of OCD (McKeon, Roa, & Mann, 1984). In one study, patients with OCD reported increased frequency and severity of significant life events (including serious illness, arguments, childbirth, and traumatic brain injury) in the 6 months prior to the onset of illness, with a peak at 1 month before onset (McKeon et al., 1984). Storch et al. (2005) reported the case of an adolescent who developed OCD after peer victimization, which was 0887-6185/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.janxdis.2011.12.001